Intra-articular ganglion cysts of the knee

Intercondylar Notch Pathology

The intercondylar notch of the knee is a relatively small area. However, numerous rare pathologies can arise in this region. A majority of the existing literature has focused on the cruciate ligament injuries, yet there are several other entities that can cause knee pain from within the intercondylar notch. This review focuses on identifying the various diagnostic and treatment options for rare benign and malignant lesions including ganglion cyst formation, mucoid degeneration, benign proliferative conditions, and intra-articular tumors. These entities are most often diagnosed with advanced imaging studies and treated arthroscopically. While rare, these pathologies are important to identify in patients with ongoing vague knee pain.

Ganglion cyst of temporomandibular joint - A systematic review

Ganglion cyst of the temporomandibular joint (TMJ) is an uncommon pathology with uncertain etiology. There is no consensus on their management. The current systematic review aimed to discuss the clinical and histopathological features of ganglion cysts of TMJ, to aid in appropriate treatment. A literature search was done and a total of 20 cases were retrieved from published databases such as PubMed, SCOPUS, and Google Scholar. The cyst presented with swelling in all the cases followed by pain (50 %) and trismus (35 %) as other common symptoms. Though CT and MRI proved helpful in determining the location of the cyst, a histopathological examination was essential in concluding its final diagnosis. It is a pseudocyst lined by dense fibro-connective tissue with myxoid tissue degeneration. Histologically, it is essential to distinguish them from the clinically and radiographically similar true cyst of TMJ, synovial cyst. The lining of ganglion cyst is devoid of epithelium and synovial cells. Surgical excision was found to be the treatment of choice with minimal recurrence (10 %) being reported.

Ganglion Cyst Resection of the Anterior Cruciate Ligament using the Posterior Trans-Septal Approach: A Report of 2 Cases

CASE

We present 2 patients each with an intra-articular ganglion cyst arising at the femoral attachment of the anterior cruciate ligament that was successfully resected using the posterior trans-septal portal approach. At the final follow-up, the patients had no recurrence of symptoms and no recurrence of the ganglion cyst on magnetic resonance imaging.

CONCLUSION

Surgeons should consider the trans-septal portal approach when they cannot visually confirm the intra-articular ganglion cyst by the arthroscopic anterior approach. The trans-septal portal approach enabled complete visualization of the ganglion cyst located in the posterior compartment of the knee.

Intra-Articular Ganglion Cysts of the Knee

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Magnetic resonance imaging (MRI) without contrast is sufficient to diagnose an intra-articular ganglion cyst of the knee. MRI with intravenous contrast may be considered for cysts in the infrapatellar fat pad, which are not a typical presentation.

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The current literature supports treating symptomatic cases or those discovered accidently during knee arthroscopy with arthroscopic excision.

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Although aspiration of these cysts results in a higher recurrence rate than excision, it is associated with quicker recovery. Thus, aspiration might be chosen as an initial treatment for anyone who would like to avoid surgery or requires a rapid recovery, including professional athletes.

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Open excision may be considered for infrapatellar fat pad cysts that are >4.5 cm in size.

Gouty tophus presenting as an anterior cruciate ligament mass in the knee: Case report and brief review of relevant literature

Introduction and importance

Tophacious gout presenting at the anterior cruciate ligament (ACL) is extremely rare and difficult to differentiate from other intraarticular pathology. This is mainly due to conventional diagnostic tools, such as MRI, producing ambiguous results versus pigmented villonodular synovitis (PVNS) and ganglion cysts.

Case presentation

Here we report an individual in their late-20s with a gouty tophus located at the origin of the ACL in the knee. Urate crystals on the articular cartilage in all three compartments was noted as well as on the synovium. On advanced imaging with an MRI, a large mass was seen anteriorly in the notch surrounding the ACL and posterior cruciate ligament (PCL). The tophus was biopsied and excised arthroscopically with excellent results.

Clinical discussion

An ACL mass in the knee has a very broad differential diagnosis. MRI imaging alone makes it very difficult to differentiate between PVNS and gout tophi yielding a pre-operative diagnostic challenge. Additionally, we review diagnostic challenges faced by other groups with similar cases, as well as their chosen treatment.

Conclusion

Gouty tophi arising from the origin of the ACL are extremely rare and remain difficult to diagnose due to their ambiguous nature in conventional imaging. In this report, we clearly convey the disparity in the diagnostic protocol for this type of intraarticular pathology. Future research should look to develop a superior protocol for identifying these pathologies to improve diagnostic accuracy.

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Atypical mass presenting at the origin of ACL, MRI unable to accurately diagnose.

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Excisional biopsy revealed tophacious gout, 1 of only 4 cases presenting at ACL.

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Multi-disciplinary approach needed in order to achieve a definitive diagnosis.

Intraligamentous synovial chondromatosis of the anterior cruciate ligament

Synovial chondromatosis is a rare disease that causes disability and dysfunction of the involved synovial joint. We describe the second case in the literature of intraligamentous synovial chondromatosis involving the anterior cruciate ligament, confirmed by pathology after arthroscopic removal of the chondral bodies. We also describe associated magnetic resonance imaging findings which may be helpful for diagnosis of this very rare entity.

Ganglion cyst of Hoffa's fat pad of knee-a rare cause of knee pain and swelling-a case report and literature review

Ganglion cysts around knee joint are uncommon and that from Hoffa's fat pad are even rarer. We present a case of 30 year old male patient with complaint of pain and swelling in left knee joint. Radiograph did not show any bony abnormality. MRI showed large tubulocystic lesion within Hoffa's fat pad which showed low signal intensity on T1-weighted images and high signal intensity on T2-STIR images. Open excision of the lesion was done. Histopathology of the specimen confirmed the diagnosis of the ganglion cyst. In follow-up, patient had asymptomatic left knee with full range of motion and did not show any sign of recurrence. Ganglion cysts from fat pad though very rare but should be considered in differential diagnosis to have an early diagnosis and management. Symptomatic ganglion cyst should be excised by open procedure or arthroscopically depending upon the size and extent of the lesion.

Intra-tendinous Patellar Ganglion Cyst Maybe the Unusual Cause of Knee Pain: A Case Report

Cystic lesion around knee usually presents as painless swelling and diagnosed incidentally by imaging for any internal derangement of the knee. Few cases presented with pain. Intra-tendinous patellar ganglion is very rare in location for the disease. Ganglionic cyst usually treated by aspiration followed by steroid and surgical excision in some cases. We reported a case with anterior knee pain due to patellar intra-tendinous ganglion cyst which treated conservatively with no recurrence even after one year.

Clinical manifestation and arthroscopic treatment of symptomatic posterior cruciate ligament cyst

Background

Ganglion cyst of cruciate ligaments is a rare lesion; the prevalence is 0.3–0.8%. The purpose of this study was to present clinical features of symptomatic posterior cruciate ligament (PCL) cyst, introduce the arthroscopic excision technique, and evaluate the clinical outcome.

Methods

A series of 11 patients with symptomatic PCL cyst from November 2012 to December 2014 were involved in this retrospective study. Detailed medical history collecting and physical examination were conducted. Magnetic resonance imaging (MRI) scan was used to confirm the diagnosis. Arthroscopic resection was performed, and the sample of the cyst was taken for pathologic examination. The follow-up averaged 30.7 months. International Knee Documentation Committee (IKDC) score, the range of motion (ROM), and MRI evaluations were obtained pre- and postoperatively to assess the surgical outcome. SPSS software was used for statistics analysis.

Results

Eight males and 3 females with 6 left knees and 5 right knees were enrolled, the mean age was 34.4 years, and the duration of symptom was 19.0 months. All cases had a definite history of knee trauma or injury. The most common symptom was knee pain at flexion or in flexion-associated activities. MRI revealed the location and size of the cyst in each case. Pathologic examination showed the cyst wall was composed of dense fibroconnective tissue and widespread thick bundles of collagen, which is similar to the structure of ganglion cyst. At the final follow-up, MRI evaluation showed no cyst recurrence. The preoperative ROM and IKDC score were 2.3° to 108.6° and 40.5 ± 11.3, respectively, compared with the postoperative ROM and IKDC score which were 0° to 134.1° and 85.5 ± 4.8 (p < 0.05) separately.

Conclusions

We conclude that the etiology of symptomatic PCL cyst is most likely associated with trauma, pain on flexion is a typical manifestation of symptomatic PCL cyst, MRI evaluation is an ideal examination for the diagnosis, and arthroscopic resection of symptomatic PCL cysts has a good outcome with no recurrence.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-0798-x) contains supplementary material, which is available to authorized users.

Extra-Articular Ganglion Cysts around the Knee Joint

Purpose

The purpose of this study was to report clinical results of open excision of extra-articular ganglion cysts around the knee joint combined with arthroscopic management of intra-articular pathologies if present.

Materials and Methods

Of the total 107 cases of cystic lesions around the knee, 23 cases of extra-articular ganglion cysts were reviewed between January 2006 and July 2011. There were 13 males and 10 females with a mean age of 48 years (range, 30 to 73 years). The mean follow-up duration was 40 months (range, 30 to 60 months). Preoperative magnetic resonance imaging (MRI) scan was done in all cases. Open surgical excision of the cyst was performed after arthroscopic management of intra-articular pathologies in all but 1 case. At the last follow-up, Lysholm and International Knee Documentation Committee (IKDC) scores were evaluated and MRI was conducted to detect recurrence.

Results

The mean Lysholm and IKDC scores showed significant improvement (p=0.005 and 0.013, respectively).The location of the cysts was anterior in 9, lateral in 7, medial in 6, and posterosuperior in 1. Intra-articular pathologies were found in 16/23 cases (69.6%). In 10/23 cases (43%), the cyst was connected to the knee joint. Three months postoperative MRI did not show any recurrence of ganglion cysts except for 1 case.

Conclusions

In the treatment of extra-articular ganglion cysts, MRI can be useful for detecting intra-articular lesions and connecting orifices, and arthroscopic management of intra-articular pathologies with open excision of the cyst should be considered as a viable treatment option.

Dual ACL Ganglion Cysts: Significance of Detailed Arthroscopy

Intra-articular ganglion cysts of the knee joint are rare and most frequently are an incidental finding on MRI and arthroscopy. Most of the previous studies have reported a single ganglion cyst in the knee. There have been previous reports of more than one cyst in the same knee but not in the same structure within the knee. We are reporting a case of dual ACL (anterior cruciate ligament) ganglion cysts one of which was missed on radiological examination but later detected during arthroscopy. To the best of our knowledge, no such case has been reported in the indexed English literature till date.

An Intra-tendonous ganglion cyst causing impingement between the anterior cruciate ligament and anterior root of the medial meniscus: a case report

BACKGROUND

There are several reports of symptomatic ganglion cysts near the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and lateral and medial meniscus, but symptomatic ganglia arising from the anterior horn of the medial meniscus to the ACL have not been reported. Here we report the arthroscopic resection of a ganglion cyst arising from the anterior horn of the medial meniscus with a meniscal tear to the ACL.

CASE PRESENTATION

A 43-year-old female presented with a 10-year history of continuous aching pain in the right knee, but without any history of trauma. Clinical examination revealed right-sided knee pain in the medial joint line, exacerbated by end range flexion and extension, a -10°-100° active range of movement, and a -5°-110° passive range of movement。McMurray's, patellar compression, and compression rotation tests were positive. Magnetic resonance imaging (MRI) and arthroscopic examination revealed a cyst related to the ACL and medial meniscus. Histological examination confirmed the cyst to be a ganglion cyst.

CONCLUSIONS

We present a new type of ganglion cyst, this is the first reported case of an ganglion cyst impinged between the ACL and the medial meniscus. It is hoped that this study will provide a better understanding of the condition and lead to better diagnosis and treatment.

Localized pigmented villonodular synovitis of the anterior cruciate ligament of the knee: an exceptional presentation of a rare disease with neoplastic and inflammatory features

Pigmented villonodular synovitis (PVNS) is a rare condition, most commonly involving the knee joint. PVNS is locally aggressive and can invade and destroy surrounding soft tissue and bone, leading to anatomical and functional deterioration of the affected joint. Localized PVNS is an unusual presentation of the disease, generally consisting of a nodular lesion protruding into the articular cavity. Localized PVNS of the knee can mimic other joint disorders which may pose a challenge for a correct diagnosis. Given the locally aggressive behavior of PVNS, prompt identification and excision of the lesion are instrumental to avoid complications. Here, we report a rare case of localized cystic PVNS involving the anterior cruciate ligament of the knee in a 32-year-old woman with persistent knee pain, in whom magnetic resonance imaging was inconclusive. The diagnosis was achieved via arthroscopy and histology. We also present a concise review of the literature on this pathological entity as well as a discussion on the differential diagnosis between localized PVNS and other intra-articular cystic lesions.

Report of ganglion cyst in the anterior cruciate ligament of a 6-year-old child

BACKGROUND

Intra-articular ganglion cysts of the knee are extremely rare within the pediatric population. To our knowledge, only seven case reports have been published in the medical literature identifying pediatric patients with intra-articular cysts of the anterior cruciate ligament (ACL). Intra-articular cysts of the knee are a rare cause of knee discomfort and mechanical symptoms such as locking of the knee. To our knowledge, up until now the youngest patient reported in the medical literature with an intra-articular ganglion cyst of the ACL was a 7-year-old boy.

CASE REPORT

We describe a 6-year-old boy who presented with a unilateral intra-articular ganglion cyst of the ACL in the right knee. In addition to the diagnostic work-up of radiographs and MRI, the cyst was successfully treated with arthroscopic resection and debridement to decompress the cyst.

CLINICAL RELEVANCE

We provide a review of the proposed pathogenesis, diagnostic modalities, differential diagnosis, treatment options, and complications of treatment for intra-articular cysts of the ACL.

LEVEL OF EVIDENCE

Level V, case report.

Falling up the stairs: the equivalent of 'bashing it with a bible' for an ACL ganglion cyst of the knee

Intra-articular anterior cruciate ligament (ACL) cysts are rare, the pathogenesis remains unknown, with trauma often implicated. Often asymptomatic, incidental MRI findings, 11% produce symptoms such as pain, locking or instability. Treatment of intra-articular ganglia differs from the traditional 'bash it with a bible' mantra for ganglia elsewhere with surgical debridement generally indicated for symptomatic cases. This case report describes a 43-year-old male car mechanic who presented with a symptomatic ACL cyst diagnosed on MRI. While waiting for surgery the patient fell up his stairs at home, causing forced hyperflexion of his knee. After an initial sharp pain, within 24 h the patient experienced complete resolution of symptoms. Postfall MRI showed no evidence of the initial lesion, leading to our conclusion that for this patient, a fall up the stairs was the equivalent of 'bashing it with a bible' for an ACL ganglion cyst of the knee.

MR findings of synovial disease in children and young adults: Part 2

Synovium is the thin membranous lining of a joint. It produces synovial fluid, which lubricates and nourishes the cartilage and bone in the joint capsule. Synovial diseases in children can be classified as normal structures as potential sources of pathology (synovial folds: plicae, infrapatellar fat pad clefts), noninfectious synovial proliferation (juvenile idiopathic arthritis, hemophilic arthropathy, lipoma arborescens, synovial osteochondromatosis, pigmented villonodular synovitis, reactive synovitis), infectious synovial proliferation (pyogenic arthritis, tuberculous arthritis), deposition disease (gouty arthropathy), vascular malformation, malignancy (metastasis) and intra-/periarticular cysts and cyst-like structures. Other intra-articular neoplasms, such as intra-articular synovial sarcoma, can mimic synovial disease in children.

Ganglion cyst of the posterior cruciate ligament

A ganglion is a fluid cyst with a myxoid matrix that arises close to the tendons and joints. Its occurrence inside a joint is rare. Among the various pathological conditions producing impairment of the knee function, ganglia of the cruciate ligaments are quite rare. It may be painful or asymptomatic. Some patients may have a trauma history. Ganglia may mimic intra-articular lesions like tears of the anterior cruciate ligament (ACL) or meniscus. Ganglia, though commonly arise from the ACL, can also arise from other structures such as the posterior cruciate ligament (PCL) or meniscus. Ganglia are typically treated by arthroscopic excision and debridement. We report a case of ganglion of the PCL in a 28-year-old man; the lesion was incidentally discovered during ACL reconstruction with double bundle (Rigid fix technique). The patient underwent arthroscopic excision of the ganglion. At the end of 1-year follow-up the patient was pain free; a full range of motion of his right knee was restored, and he returned to his preinjury sport activity.

Hoffa's fat pad impingement treated arthroscopically: related findings on preoperative MRI in a case series of 62 patients

INTRODUCTION

The morphology of painful impingement of the infrapatellar fat pad (Hoffa's disease), which is characterized by inflammation, swelling, hypertrophy, fibrosis, and/or calcifications, has been well described. The purpose of this study was to investigate whether corresponding characteristic MRI findings could be assessed in patients with infrapatellar fat pad impingement.

MATERIALS AND METHODS

This study includes 62 patients with secondary symptomatic Hoffa's fat pad impingement. In these patients, the fat pad was partially resected until no impingement could be determined at full knee movement. Within a maximum of 3 months before arthroscopic surgery, patients had standardized MR imaging using a 1.5 Tesla unit with the following sequences: sagittal T1-TSE, coronal STIR-TSE, transversal fat-suppressed PD-TSE, and sagittal fat-suppressed PD-TSE (Siemens Magnetom Avanto syngo MR B 15). In this case series, the preoperative MRI appearance of the fat pad was evaluated and compared with a cohort of 255 patients without fat pad impingement but with various knee disorders at arthroscopy as well as the same standardized MRI protocol.

RESULTS

In patients with Hoffa's fat pad impingement, morphologic changes such as localized edema of the superior and/or posterior part of the fat pad, a deep fluid-filled infrapatellar bursa, non-visualization of vertical and/or horizontal clefts, fibrosis, and calcifications were noted on MR imaging with remarkable frequency. Besides a significant enlargement of the fat pad, each of these MRI findings was significantly associated with impingement of Hoffa's fat pad (P < 0.05). Besides a moderate kappa score for the detection of intrahoffatic calcifications and vertical clefts, kappa values for each finding showed good inter-observer agreement. Results of logistic regression revealed that edema of Hoffa's fat pad was one of the most important diagnostic MRI criteria for the diagnosis of Hoffa's fat pad impingement.

CONCLUSION

MR imaging allows identification of several changes that may be related to a symptomatic impingement of Hoffa's fat pad. In patients who are suspected of having infrapatellar fat pad impingement, such MRI findings should be considered and distinguished from other causes of anterior knee pain.

Preoperative localization of cystic lesions in the knee using ultrasound-guided injection of indigo carmine

PURPOSE

To evaluate the feasibility and effectiveness of preoperative localization of cystic lesions in the knee using ultrasound-guided indigo carmine injection.

METHOD

Twenty-three cysts in the knee in 23 patients (M:F = 15:8, mean age, 42 years) were localized preoperatively by ultrasound-guided indigo carmine injection. These included 12 meniscal cysts, 7 popliteal cysts, and 4 ganglion cysts. To stain the lesions, 0.2-3 mL of indigo carmine was injected into the cyst using a 22-gauge spinal needle. After localization, the patient was immediately transferred to the operating room and surgery was performed. Intraoperative findings and arthroscopic images were reviewed.

RESULT

All 23 cysts were stained successfully. Twenty cases were confirmed during arthroscopy and 3 cases were confirmed during excisional surgery. There was no significant bleeding/hematoma or anaphylactic reaction. Four patients felt pain during aspiration before indigo carmine injection. The lesions were stained blue and could be clearly identified by the surgeon and were removed arthroscopically or by open surgery.

CONCLUSION

Preoperative localization of cystic lesions in the knee joint region using ultrasound-guided indigo carmine injection is a feasible technique and can be easily and safely be performed.

Ganglion cyst of the anterior cruciate ligament in children

The incidence of ganglion cysts of the anterior cruciate ligament (ACL) has increased significantly since the advent of MRI, but it remains exceptional in children. We report the case of a 7-year-old boy, with an exceptional imaging exam and histological finding of a ganglion cyst. The lesion was at first an MRI finding with a hypointensity signal on T2-weighted sequences of a normal ACL. An arthroscopy was performed that showed a cyst measuring 40 mm filling the intercondylar notch and involving the roof and the edges of the ACL. A cystography confirmed the position of the cyst, which was removed with specific management of the ACL. Histological examination confirmed the absence of mucoid degeneration, which is always observed in adult lesions. We believe that the ganglion cyst of the ACL in children differs in pathogenesis from common degenerative cyst in adults.

Multiple ganglion cysts (‘cystic ganglionosis’): an unusual presentation in a child

A case of multifocal and recurrent ganglion cysts is described. An 11-year-old boy was referred because of symptomatic cystic masses in the extremities since the age of 2 years. Over the years, he had experienced intermittent appearance of these lesions, which were associated with pain, but without any systemic manifestations. Magnetic resonance imaging (MRI) showed cystic lesions with synovio-capsular thickening along the temporomandibular joints (TMJ), atlanto-axial synovial articulation, and tendons and joints of the right wrist and hand. Histopathological examination of one lesion showed anastomosing fibro-connective tissue surrounded by a wall of smooth muscle and fibrous connective tissue, findings that were consistent with ganglion cyst. The early onset of the disease, as well as the involvement of multiple and unusual sites, including the TMJ, implies a genetic susceptibility to these lesions that we refer to as 'cystic ganglionosis'.

MRI features of cystic lesions around the knee

Cystic lesions around the knee are a diverse group of entities, frequently encountered during routine MRI of the knee. These lesions range from benign cysts to complications of underlying diseases such as infection, arthritis, and malignancy. MRI is the technique of choice in characterizing lesions around the knee: to confirm the cystic nature of the lesion, to evaluate the anatomical relationship to the joint and surrounding tissues, and to identify associated intra-articular disorders. We will discuss the etiology, clinical presentation, MRI findings, and differential diagnosis of various cystic lesions around the knee including meniscal and popliteal (Baker's) cysts, intra-articular and extra-articular ganglia, intra-osseous cysts at the insertion of the cruciate ligaments and meniscotibial attachments, proximal tibiofibular joint cysts, degenerative cystic lesions (subchondral cyst), cystic lesions arising from the bursae (pes anserine, prepatellar, superficial and deep infrapatellar, iliotibial, tibial collateral ligament, and suprapatellar), and lesions that may mimic cysts around the knee including normal anatomical recesses. Clinicians must be aware about the MRI features and the differential diagnosis of cystic lesions around the knee to avoid misdiagnosis.

Intra-articular ganglia of the knee joint associated with the anterior cruciate ligament: a report of 4 cases in 3 patients

Intra-articular ganglia are rare and mostly incidental findings on magnetic resonance imaging (MRI) and arthroscopy. We present 4 cases of intra-articular ganglion cysts associated with the anterior cruciate ligament (ACL) in 3 patients. The most commonly occurring symptoms were pain aggravated after stressing activities and limited knee range of motion. In 1 patient, ganglion cysts appeared in both knees with a time difference of 1 year. An MRI revealed typical signs of ganglion cysts in the substance of the ACL. Arthroscopy was performed for further evaluation and treatment. Histologic examination of the tissue removed revealed the presence of features consistent with ganglion cysts. Therefore, in the case of chronic knee discomfort with nonspecific clinical signs and symptoms and without a clear cause, an intra-articular ganglion cyst should be considered as causing pathology. An MRI is the most sensitive and specific method for diagnosis. However, the relatively slow progression of symptoms may delay the patient's decision to seek medical attention. Delayed diagnosis makes arthroscopic total resection of the ganglion technically demanding or not possible at all, and extensive debridement of the ACL may be required.

Snapping knee symptoms caused by an intra-articular ganglion cyst

Snapping knee syndrome describes the sudden movement of a soft-tissue structure across a bony prominence around the knee with a popping sound at some specific activity. Symptomatic snapping knee syndrome may result from an intra-articular tumor, but this situation is rare. To the best of our knowledge, an intra-articular ganglion cyst leading to snapping knee has not been reported previously. A 20 year old female with painful snapping knee was successfully treated by open en-bloc excision of the ganglion cyst sized 4.5 x 1.5 x 1 cm on the ligamentum mucosum. Snapping and pain were completely relieved after surgery. Although the snapping knee is not common over the antero-lateral portion of the knee joint, a ganglion cyst from the ligamentum mucosum is a possible cause.

Conservative treatment for a symptomatic solitary ganglion cyst of the anterior meniscus invading into the infrapatellar fat pad

Symptomatic meniscal cysts without accompanying meniscal tears are uncommon, especially those which are formed from the anterior meniscus and invading into the infrapatellar fat pad (IPFP). The current recommended treatment for such cysts is excision through open method or arthroscopy. To our knowledge, this is the first case study about a symptomatic solitary meniscal cyst invading the IPFP that was successfully treated with needle aspiration and steroid injection after arthroscopic treatment of the associated disorders. In this paper, similar cases are also reviewed to discuss the treatment and the link between meniscal cyst and meniscal tear.

Ganglion cysts at the gastrocnemius origin: a series of ten cases

OBJECTIVE

To describe ganglion cysts arising close to the origin of the medial and lateral head of gastrocnemius as identified on magnetic resonance (MR) imaging.

DESIGN AND PATIENTS

We present a series of ten cases of ganglion cysts arising close to the gastrocnemius origin from the medial and lateral femoral condyles. These were collected over a 6-year period from our imaging database. All patients attended for routine MR imaging of the knee with a variety of clinical presentations. Data collected included patient demographics, ganglion size, ganglion site, clinical presentation and ancillary MR imaging findings. The ten patients in this series consisted of seven males and three females, five right and five left knees, age range 27-68 years, mean age 40.6 years.

RESULTS

The mean maximal dimension of the ganglion cysts was 26 mm, range 15-40 mm. The medial gastrocnemius origin was involved in eight patients and the lateral origin in two patients. The MR imaging findings consisted of both uni- and multi-loculated cysts, often containing numerous septations with fluid signal characteristics. The cysts were extra-capsular with no clear communication with the joint. One patient presented with a popliteal soft tissue mass and none of the cases required surgical intervention for cyst removal.

CONCLUSIONS

MR imaging may identify ganglion cysts arising in an intra- or extra-articular site around the knee. This series documents the MR imaging characteristics of ganglion cysts arising close to the gastrocnemius origin and discusses the relevance of this imaging finding.

An intra-articular knee cyst in a 2-year-old associated with an aberrant anterior cruciate ligament

Intra-articular ganglia of the knee occur infrequently, with an overall incidence estimated to be from 0.2 to 1.9%. To date, the youngest patient reported with an intra-articular ganglion was an adolescent. In this paper, we describe a 2-year-old patient with a massive intra-articular knee cyst and an aberrant anterior cruciate ligament (ACL) origin. The cyst was successfully treated with arthroscopic debridement. Proposed pathology and treatment recommendations for intra-articular cysts are reviewed.

Tumor-like meniscal cyst

A 50-year-old woman presented with a 5-year history of mild pain in her right knee, which had increased over the last 2 years. A palpable mass over the anterolateral aspect of the knee was obvious and the last 3 months she was experiencing locking episodes with consequent knee effusion. The differential diagnosis was driven between meniscal cyst, pigmented villonodular synovitis, synovial sarcoma, synovial chondromatosis, and aneurysm. After a diagnostic arthroscopy, the lesion was excised by a limited lateral arthrotomy. The pathologic findings revealed a synovial cyst. Intra-articular synovial cysts are uncommon, nonsymptomatic, and mostly incidental findings on magnetic resonance imaging (MRI) and arthroscopy. This lateral meniscus synovial cyst (2.5 x 2.5 cm) was enlarged within the intracondylar notch and produced disabling knee symptoms. The peculiarity of this lesion was the tumor-like appearance: its large size, the progress of symptoms, and the multilobulated, nonhomogenous signal on the MRI scan. One year postoperatively, the patient is asymptomatic and the MRI obtained at 6 months revealed no remnant of the fully excised cyst.

The modified outside-in suture: vertical repair of the anterior horn of the meniscus after decompression of a large meniscal cyst

This article describes a modified suture technique designed for the vertical repair of the anterior horn of the meniscus after arthroscopic decompression of a large meniscal cyst. This procedure comprises of three steps: first, the meniscus was pierced vertically using a suture hook and a No. 0 PDS suture. Second, both ends of the No. 0 PDS on the femoral and tibial surfaces of the meniscus were pulled to the outside of the joint capsule using a spinal needle preloaded with suture material. Finally, a skin incision was made adjacent to the suture materials, and both ends were tied. We recommend this technique not only for the vertical repair of the anterior horn of the meniscus after decompression of large meniscal cyst, but also to repair a longitudinal tear of the meniscus.

Locked knee caused by intraarticular ganglion

Intraarticular ganglion cyst arising from the cruciate ligament is difficult to diagnose by clinical symptom. In our case, Cyst attached anteriorly to posterior cruciate ligament, and limited both flexion and extension of knee. The cyst was excised in a piecemeal fashion arthroscopically. Knee pain and limitation in knee motion disappeared by the day after surgery. We hypothesize that reason of restriction of extension is impingement between anterior cruciate ligament and intracondylar, and reason of restriction of flexion is stimulation nerve ending in the synovial membrane stretched with knee motion.

Large extrasynovial intracapsular ganglia of the knee: a report of 3 cases

PURPOSE

Intra-articular ganglia of the knee are rare and usually incidental findings of little clinical significance. Nevertheless some are large, symptomatic, and require treatment. We report on 3 patients with an intra-articular knee ganglion and an extrasynovial extension that was contained within the joint capsule. This seems to be a rare condition; a review of the English-language literature revealed no reports of similar cases.

TYPE OF STUDY

Case series.

METHODS

Three patients, 1 man and 2 women aged 27 to 40 years, presented with an almost identical history of anterior knee pain that had been treated conservatively for a long time as chondromalacia patellae. The symptoms, which were ill-defined, appeared to be deteriorating until a localized swelling appeared on the lateral side of the patella tendon in each case. On examination, a lateral meniscal cyst associated with an underlying meniscal tear was suspected. However, magnetic resonance imaging revealed a ganglion arising from the substance of the anterior cruciate ligament (case 1) and from the area of the tibial insertion of the anterior cruciate ligament (cases 2 and 3). All 3 ganglia extended anteriorly and then laterally over and in front of the lateral meniscus. The ganglia were approached through an anterior midline incision and lateral parapatellar arthrotomy, which allowed direct and easy access for complete excision. Histologic examination confirmed the diagnosis of a ganglion in all 3 cases.

RESULTS

The postoperative course was uneventful in all patients with no signs of recurrence at 1 year (case 1), 2 years (case 2), and 3 years (case 3).

CONCLUSIONS

Although the described condition seems very rare, we believe that it should be included in the differential diagnosis of cystic lesions about the knee joint.

LEVEL OF EVIDENCE

Level IV, case series, no, or historical control group.

Posterior Cruciate Ligament Recess and Normal Posterior Capsular Insertional Anatomy: MR Imaging of Cadaveric Knees

PURPOSE

To analyze the normal pattern of fluid accumulation adjacent to the posterior cruciate ligament and anatomic variations of joint capsule insertion sites in the posterosuperior corner of the human knee by using magnetic resonance (MR) imaging in cadaveric specimens.

MATERIALS AND METHODS

Fourteen fresh cadaveric knees (obtained and used according to institutional guidelines, with informed consent from relatives of the deceased) from 11 men and three women (six left knees, eight right knees; age range, 70-82 years at time of death; mean age, 76 years +/- 4.4 [standard deviation]) were studied with high-spatial-resolution MR imaging performed before and after intraarticular injection of 35-45 mL gadopentetate dimeglumine. MR images were evaluated by two readers in consensus, with emphasis on location of fluid posterior to the posterior cruciate ligament, communication of that fluid with the medial or lateral compartment of the knee, and the relation of fluid to surrounding structures. Readers also were asked to measure, in the sagittal plane, the distance between the posterior capsular insertion sites and the femoral physeal scar. For anatomic analysis, cadaveric specimens were sectioned in 3-mm-thick slices in the sagittal plane that approximated the sections acquired at MR imaging.

RESULTS

In all 14 cadaveric specimens, MR arthrographic images showed a fluid collection behind the posterior cruciate ligament (in the posterior cruciate ligament recess), a finding not evident on images obtained prior to contrast material injection. The recess was distended during flexion, and it communicated only with the medial femorotibial compartment in all cases. Posterior to the posterior cruciate ligament recess, a fat pad was observed in all specimens. Incomplete joint capsule was seen behind the fat pad in seven specimens. Joint capsule insertion was at the level of the femoral physeal scar or between it and a point 15 mm above it.

CONCLUSION

The posterior cruciate ligament recess has specific characteristics that allow its identification: communication with the medial compartment of the knee and absence of the adjacent joint capsule.

Ganglion cyst of the anterior cruciate ligament: a case report

A ganglion is a cystic swelling that usually arises close to tendons or joints. Its occurrence inside a joint is rare, and its diagnosis is usually incidental during magnetic resonance imaging or arthroscopy. It may be painful or asymptomatic. Some patients may have a trauma history. Ganglia may mimic intra-articular lesions like tears of the anterior cruciate ligament or meniscus. Magnetic resonance imaging is the investigation of choice for diagnosis. Ganglia commonly arise from the anterior cruciate ligament, but can also arise from other structures such as the posterior cruciate ligament or meniscus. Ganglia are typically treated by arthroscopic excision and debridement. We report a case of ganglion cyst of the anterior cruciate ligament in a 16-year-old man.

The infrapatellar fat pad: anatomy and clinical correlations

This study examined the anatomy of the infrapatellar fat pad (IFP) in relation to knee pathology and surgical approaches. Eight embalmed knees were dissected via semicircular parapatellar incisions and each IFP was examined. Their volume, shape and constituent features were recorded. They were found in all knees and were constant in shape, consisting of a central body with medial and lateral extensions. The ligamentum mucosum was found inferior to the central body in all eight knees, while a fat tag was located superior to the central body in seven cases. Two clefts were consistently found on the posterior aspect of the IFP, a horizontal cleft below the ligamentum mucosum in six knees and a vertical cleft above, in seven cases. Our study found that the IFP is a constant structure in the knee joint, which may play a number of roles in knee joint function and pathology. Its significance in knee surgery is discussed.

Intra-articular cysts and ganglia of the knee: a report of nine patients

Completely intra-articular cysts and ganglia of the knee are rare. They have been found in various locations such as on the anterior or posterior cruciate ligaments, in the infrapatellar fat pad, on the posterior wall of the posteromedial compartment and (very rarely) in connection to the menisci. We analyzed nine patients with intra-articular cysts or ganglia found in a series of 2,400 consecutive arthroscopies. In four patients, the cyst or ganglion was found attached to the anterior part of the ACL, in two patients it was located between the ACL and the PCL, and in the remaining three cases it was found in connection with the meniscus. In three out of the nine patients there was either no or very minor additional pathology found in the knee besides the cyst or the ganglion. We believe that intra-articular cysts and ganglia of the knee can be symptomatic, and excellent or good results after cyst removal can be expected especially when there is little additional pathology.

Hoffa's recess in the infrapatellar fat pad of the knee on MR imaging

The infrapatellar fat pad of Hoffa is a structure that is located in the space between the back side of the patellar ligament and the real capsule. It is routinely visualized on magnetic resonance (MR) images of the knee. The purpose of this study was to determine the prevalence and shape of a fluid-like indentation at the inferior posterior margin of the infrapatellar fat pad of the knee (recess) and to look for a relation between the liquid image in the fat pad and joint effusion. Three hundred and fifty consecutive MR imaging examinations of the knee were evaluated for the presence, location, size and shape of a recess in the infrapatellar fat pad and existence of joint effusion. The study population consisted of 145 females and 205 males aged between 5 and 80 years old (mean age 37.5 years). The recess in the infrapatellar fat pad was revealed on MR imaging in 54 of 350 knees (15.43%) and had a variable shape, consisting of 35 linear or ovoid (64.81%), five pipe-shaped (9.26%) and 14 globular (25.92%). Additionally, one ganglion cyst was observed in the infrapatellar fat pad. Globular and pipe-shaped recesses may be confused with cystic infrapatellar fat pad pathologies such as ganglion cyst, meniscal cyst, loose body or nodular synovitis. The existence of an infrapatellar fat pad may not be related to the presence of joint effusion.

Intra-articular ganglia arising from the posterior joint capsule of the knee

Magnetic resonance imaging (MRI) is an effective method to evaluate cystic lesions of the knee. Intra-articular ganglia of the knee joint was considered to be rare before the advent of MRI. However, because an MRI is often used to diagnose knee pathology, the reported prevalence of intra-articular ganglia has increased. We describe two cases of an intra-articular ganglion arising from the posterior joint capsule. Both cysts appeared to be arising from the posterior cruciate ligament by both MRI as well as arthroscopy through a lateral infrapatellar portal. However, arthroscopy through a posteromedial portal revealed the cysts to originate from the posterior joint capsule. It suggests that some of the ganglion arising from the posterior cruciate ligament reported in the literature might actually be from the posterior joint capsule. To prevent recurrence of a ganglion cyst, when preoperative MRI shows the mass to be located posterior to the cruciate ligaments, we recommend that the relationship of the ganglion cyst to the posterior joint capsule be evaluated at arthroscopy through the posteromedial or posterolateral portal.

Large lateral meniscal ganglion cyst extending into the intercondylar fossa of the knee

We report the case of a 31-year-old, otherwise healthy man with a large intra-articular meniscal ganglion cyst (27.7 x 13.5 mm) originating from the dorsal horn of the lateral meniscus. Clinically, the patient presented with knee pain in a squatting position. Magnetic resonance imaging revealed a large intra-articular cyst in the posterior compartment. At arthroscopic surgery, the ganglion cyst was found in the intercondylar space posteriorly to the posterior cruciate ligament. After removal of the ganglion cyst, a horizontal tear in the dorsal horn of the lateral meniscus was revealed and treated by partial meniscectomy. To our knowledge, a meniscal ganglion cyst originating from the lateral meniscus and extending into the joint is an extremely rare event, with only two previous reported cases. We review the current literature on the pathogenesis, distribution, and treatment of meniscal ganglion cysts.

Ganglion cysts of the posterior cruciate ligament

Ganglion cysts arising from the posterior cruciate ligament (PCL) of the knee are rare. Thirteen cases have been reported with detailed description in the English literature. In this study, 3 cases of ganglion cyst arising from the PCL of the knee are described and comparatively reviewed with the literature. This case report draws attention to clinical symptoms and signs. We presume that rather than mechanical block, it is changes in the shape and dimension of the ganglion cyst with knee motion and posture that stimulate nerve endings in the synovial membrane, causing the development of knee pain and the limitation of knee motion.

A giant ganglion cyst that developed in the infrapatellar fat and partly extended into the knee joint

Ganglion cysts of the knee joint usually present near the lateral meniscus. Their size varies, and they may be encased in single or multiple capsules. Few case reports on ganglion cysts of the knee joint have been reported. We report a giant ganglion cyst that developed in the patellar fat and partly extended into the joint. The ganglion cyst was exposed in the meniscosynovial junction and was electrically evaporated at the anterior horn. No recurrence has occurred to date, and the patient has returned to his previous level of activity.

Intra-articular ganglion cysts of the cruciate ligaments: case report and review of the literature

BACKGROUND

A ganglion can arise as a cystic lesion from a tendon sheath or a joint capsule and contain a glassy, clear, and jelly-like fluid. They can occur within muscles, menisci, and tendons. Intra-articular ganglion cysts of the knee joint are rare. We report on three ganglion cysts of the cruciate ligaments: Two were intercruciate, and one was located around the posterior cruciate ligament.

METHODS

The clinical diagnosis was established using magnetic resonance imaging. All patients were treated successfully using arthroscopic debridement by basket punch and shaver. Subsequent histological examination confirmed the diagnosis.

RESULTS

All three patients were asymptomatic at the postoperative follow-up of 16-36 months.

CONCLUSION

A review of the literature reveals a controversial discussion about the clinical significance as well as the etiology of ganglion cysts arising from the cruciate ligaments. These case reports show that an intra-articular ganglion cyst of the cruciate ligaments is difficult to diagnose. A cyst does not necessarily have to be associated with specific clinical symptoms or a previous trauma. Preoperatively, MRI is essential when diagnosing ganglion cysts of the knee joint. An intra-articular ganglion cyst of the knee joint can be successfully treated by arthroscopy.

Prevalence and size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections in asymptomatic knees on MR imaging

OBJECTIVE

The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees.

MATERIALS AND METHODS

MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured.

RESULTS

Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees.

CONCLUSION

Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

Arthroscopic ganglion cyst excision in the anterolateral aspect of the knee

We present a case of ganglion cyst of the knee treated arthroscopically. Ganglion cysts typically arise from the anterior or the posterior cruciate ligament. In this case of an anomalous location, a 3.5-cm mass arose directly from the anterolateral articular capsule, lying over the lateral meniscus, displacing Hoffa's fat pad and joining the pretibial bursa. We removed it arthroscopically using only medial portals to avoid cystic wall damage and fluid leakage from the lateral portal. Arthroscopic evaluation was performed starting from the inferomedial portal to assess the cyst location, and shifting to the mid patellar portal. From that portal, we were able resect the cyst, opening the wall and shaving and aspirating the myxoid fluid.